Hello gentlemen... first off, thanks in advance for any and all comments, everyone is always helpful on this site. I am have a small issue with my John Deere 510 Backhoe/Loader. Everything seems to be working fine, well, fine enough for a nearing 40 year old machine, but I have recently been getting a high pitch noise, almost like a squeak when I extend or retract the boom and/or dipper on my backhoe. Left or right of the boom is fine, up and down with the bucket is fine. Also, no sounds on the loader side so I don't think there is anything up with the pump. So, I am thinking that maybe there is a piece of garbage in the valves or o-rings getting ready to fail?? No leaks are visible. Anyone ever run into a similar issue?
sounds low on hyd. oil
If their greased then it could be the relief valve making the noise.
The fluid level seems ok and is at the bottom quarter of the OK range. I may bring that up to mid way so that I can eliminate it. I am thinking air may be getting sucked in there somehow, possibly in the manifold feeding the boom and dipper.
What does the fluid look like after it's been used for a while? any foamy or milky look to it? Have you changed grease brands lately, or bent the backhoe? The only thing that comes to mind (other than GREASE) is the hydraulic system is mostly closed, in that most of the return flow goes right back to the pump, with the excess return going out a pressure control valve, and the extra supply for the pump being made up by a charge pump. I'd think that would make a different sound each direction if one of those were causing the problem though? Does the noise sound similar going in and out?
Sound is similar going in and out. I will investigate and try to put a video up on YouTube later today. The fluid doesn't doesn't appear foamy or milky.
Only other thing I can think of that's hydraulic related is the volume required for those functions could be dropping the charge pressure, or making your hydraulic pump make more noise? Can you tell where the noise is coming from? And see if it makes the same noise empty and in the air, vs digging normally, vs digging too deep and almost stalled.
So I put a stethoscope on everything on the backhoe while operating the boom and dipper. Not the dipper, just the boom. It seems, that it may be a grease issue at the bottom grease fitting. After listening to it with the stethoscope I am about 85% sure it is grease... update coming soon. I hope I am right and appreciate everyone that chimed in.
So call me an idiot... I pulled off the grease fitting, cleaned it, greased it and whoa and behold, no squeak or whine. Of course the machine paid me back for not trusting it and blew a hose 30 mins later.